阴土蛇年(female Earth-Snake)−224 or −605 or −1377— to —阳金马年(male Iron-Horse)−223 or −604 or −1376

Year 351 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Peticus and Crispinus (or, less frequently, year 403 Ab urbe condita). The denomination 351 BC for this year has been used since the early medieval period, when the Anno Dominicalendar era became the prevalent method in Europe for naming years.

Demosthenes tries to get the Athenians to cease depending on paid mercenaries and return to the old concept of a citizen army. He also delivers his First Philippic, warning Athenians of the folly of believing that Philip's ill health will save Athens from the Macedonians. In response, Athens' citizens votes for increased armaments.